Huanglian can be used externally to treat carbuncle boils (sores on the limbs or face, small in shape with deep roots, as hard as nails), eczema, wet sores and other skin diseases, and is usually effective in clearing heat and drying dampness (removing heat and drying out dampness), and laxative and detoxicating (dispelling fire and toxicity in the body) to the skin. Huanglian is bitter in flavor and cold in nature, and can be used externally to treat skin diseases caused by higher dampness and heat, and heat-toxicity blazing (overly exuberant fire evil in the body). For example, for carbuncles and boils on the skin, which are characterized by redness, swelling, heat and pain, it can be boiled in water and then washed externally on the local skin; in addition, for eczema and wet sores which are characterized by burning, pain, itching, as well as yellowish water after scratching and ulceration, Huanglian can be used externally to treat them as well. When treating these skin diseases, Huanglian can be used externally, but also can be decocted and taken internally, so that the internal and external use of the combination of skin diseases have a better therapeutic effect. However, it should be noted that Huanglian is bitter and cold, and is not suitable for skin diseases caused by yang deficiency, such as skin abscesses, but not red, mild pain, ulcers that do not heal for a long time, and local color darkening, can not be used for treatment. If you suffer from skin diseases, it is recommended to consult a doctor in a timely manner, under the guidance of a traditional Chinese medicine practitioner, to identify the evidence of prescription treatment, do not abuse the drug.